Add coverage for meta data import and lock/txn operations

Author: terrymanu

proxy/backend/core/src/test/java/org/apache/shardingsphere/proxy/backend/util/MetaDataImportExecutorTest.java

@@ -109,7 +109,7 @@ private ExportedMetaData createExportedMetaData() {
     }
 
     @SneakyThrows(ReflectiveOperationException.class)
-    private void setField(Object target, String fieldName, Object value) {
+    private void setField(final Object target, final String fieldName, final Object value) {
         Plugins.getMemberAccessor().set(MetaDataImportExecutor.class.getDeclaredField(fieldName), target, value);
     }
 }